Electromagnetic (EM) modeling plays an important role in reliable target detection and recognition for SAR data exploitation. EM modeling provides target EM observables and metrics such as the expected image or radar cross section (RCS) that characterize and identify targets based on their signatures. Hence, it serves as an important reference to identify unknown scatterers. Here, a generic framework for the EM formulation of target signatures is developed. Various signatures for certain targets of interest are derived and analyzed using analytic techniques and numerical prediction tools.